When tracking particles, if either the [;USRB Record background intensity] option has been chosen or [;USPB Enable background pricing] is set, it is necessary to estimate the intensity of the image surrounding a particle. This is achieved by evaluating the intensity histogram within a window centred on the particle and searching for the modal value which specifies the local background. The intensity is divided into eight discrete steps between a specified lower and upper limit. The local background will be assigned to one of these eight steps.
Note that background intensities will not be evaluated if the tracking is started by the [;UH Start particle tracking - 4095 particles] option.
This option specifies the height of the window (in pixels) to be used when determining the local background.
This option specifies the lower limit set on the intensity for the background. If the local background appears darker than this, then it will be assumed to be at this level.
This option specifies the upper limit set on the intensity for the background. If the local background appears lighter than this, then it will be assumed to be at this level. Note that this intensity should be less than or equal to the less stringent (lower) threshold.
This option specifies the width of the window (in pixels) to be used when determining the local background.